This invention relates to an image forming apparatus, more specifically, the invention relates to an apparatus for reproducing a copy image according to either a positive original image or a negative original image.
There is known a microfilm reader printer for projecting a reduced image recorded on a microfilm onto a screen and reproducing copies of the desired image recorded on the microfilm. Generally, the recorded images of microfilms are roughly classified into two categories, i.e., positive images and negative images. Therefore, two types of developing processes are performed in order to reproduce a copy image from these two different kinds of microfilm images. To meet this requirement, a first developing device for reproducing a positive copy image from a positive microfilm image and a second developing device for reproducing a positive copy image from a negative microfilm image are mounted on the machine and only one of these developing devices is activated according to the kind of microfilm images.
An example of such an apparatus is disclosed in U.S. Pat. No. 4,341,463. This microfilm reader printer has a first developing station for normal development and a second developing station for reversed development. Each developing station contains a liquid developer, a pump and a pipe, respectively. It is, therefore, difficult to achieve lightweight and low-cost arrangements.